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Wednesday, November 23, 2016

Ron Swanson (Nick Offerman) on Making Things and Making Mistakes

Driving home from work the other day I heard this NPR interview with the woodworking guy from the TV show "Parks and Recreation."  I've never seen the show, but I really liked the comments on the benefits of what we would call homebrewing:

MCEVERS: I feel like there are a lot of people out there listening who have spent exactly zero days being handy, like, their entire lives. Is there hope for people like this, and does your book provide it?

OFFERMAN: I think so. I mean, a lot of my own woodworking education comes from books and periodicals like Fine Woodworking and Popular Woodworking magazines. They're great teachers, but they're very somber. They're very sober. So it was important to me for this book to be really friendly and gentle and fun to let you know that whether you're getting into woodworking or making anything with your hands, it's really important to know going in that you're supposed to make mistakes. You're supposed to screw it up.

And not only do I think this is a very friendly introduction to woodworking, but I really have become a little bit of an evangelist to encourage - find something to make. If you make stuff for your house or your loved ones, you're curating your life in a way, saying, I don't have to just limit my choices to what I can buy at Amazon. I can also choose to make a table myself. And even if it looks crappy, it's still so much more charming because you've made that gesture.

You can listen to the 6 minute interview (it is funny) by clicking on the "PLAY" arrow in the upper left of this page:  

http://www.npr.org/2016/11/17/502476216/nick-offerman-shares-his-love-of-woodworking-in-good-clean-fun

Tuesday, November 22, 2016

HB2HB! Pete Talks to Famed SSDRA Project Builder Jeff Damm WA7MLH


Jeff "Roadkill" Damm 

Wow, THE RADIO GODS HAVE SPOKEN (TRGHS).  Pete gets on 40 with his new-old FPM5 homebrew rig and works homebrew legend Jeff Damm WA7MLH, who was also running a homebrew SSB rig.   HB2HB!   For those of you who don't know, Jeff is the guy who built many of the inspirationally ugly rigs in Solid State Design for the Radio Amateur.  Pete's second QSO was with SolderSmoke podcast listener K7ADD.  TRGHS! 

Hi Bill,
Was on 40M yesterday with the FPM5 rig and after finishing a QSO was called by WA7MLH (Jeff Damm –the road kill guy and protégé of Wes Hayward). Jeff was operating portable 7 in NW Montana running a homebrew 40 Watt SSB transceiver off of batteries being charged by a solar panel. Now that is real radio. I thanked him once again for sending me a goodie box about 5 years ago and am still using those parts.
Later after another QSO was called by K7ADD, Ben, and he couldn’t wait to tell me he was a long time SS listener and stated listening to SS made him take a whole new interest in ham radio –especially building stuff.
So you never know.

Pete

Sunday, November 20, 2016

Homebrew Processor with Discrete Transistors and LEDs



I've been working with an Arduino today.  Seeing this video makes me feel like such an APPLIANCE OPERATOR.  FB OM!  No store-bought mystery boxes for him! 

Thanks to Steve N8NM for alerting us to the magnificent project.

More details here:

http://www.popsci.com/man-builds-huge-megaprocessor

Saturday, November 19, 2016

Analog TO THE MAX! An Old School Readout for the BITX 40

Perhaps this was a reaction to a frustrating morning spent trying to get a 20x4 digital display to work with an Si5351 and an Arduino Uno via an I2C bus (I feel my blood pressure rising just due to the typing of those words).   After much digital fiddling, I declared a "BASTA!"  and looked around the shack for an antidote for the digital frustration.  There on the bench was my fully analog BITX40Module rig, with its homebrew L-C analog VFO.   It needed a better frequency readout. And this morning, it got one.  

The pointer is Sharpie ink on a bit of PC board.  It is held in place by superglue, suspended by a piece of wood about 1/4 inch off the chassis (to reduce dial parallax).  The numerals are in Dymo tape -- there was not enough room for the "7" but I think I will be able to remember this. 

Very therapeutic and satisfying.   

Tuesday, November 15, 2016

25 Watts From a Single IRF510

I should have tried this a long time ago.  It works great.  The power supply that I picked up at the Kempton Park rally many years ago  happens to have a 25 volt unregulated output.  Coincidence you say?  I think not.  TRGHS.  

 Farhan provides a really excellent description of how to do this:
http://hfsignals.blogspot.com/p/25-watt-linear-for-40-and-20.html

Monday, November 14, 2016

"Sideband Suzy" and the History of SSB

Farhan alerted us to a very interesting presentation on the history of single sideband:  It was in episode 81 of Bob Heil's "Ham Nation" show.  It starts at minute 22:

https://www.youtube.com/watch?v=xSF0WBdK1IQ&feature=youtu.be

Two things really caught my attention:

-- Note how OM Carson, way back in 1915, had figured out how to get rid of the carrier, but needed some way of eliminating the unnecessary sideband.  He did it by using his antenna tuner as a filter.  FB OM!

-- In the early days of SSB, when it was an exciting new technology, hams had regular "sideband dinners."  At these events an award was presented.  Kind of like an Oscar or an Emmy I guess.   The award was the "Sideband Suzy" (see above).    Kind of a classic figure...  but half of Suzy was missing!




Saturday, November 12, 2016

Putting a Heatsink on the BITX40 Module

The fan that I installed yesterday was driving me nuts.  It was noisy, both acoustically and electrically.  And I would occasionally get my fingers in the blades.  Not good.  While it did seem to keep the IRF510 from getting too hot, I knew that a real heatsink would do better thermally.

But how was I going to attach the sink to the transistor?  That tab on the IRF510 goes to the collector, so if it touches a grounded heat sink, you get a short.   A nylon screw and some mylar between the transistor tab and the heat sink is one option.  But I didn't have a nylon screw.  So I decided to just keep the heat sink electrically insulated from the chassis.

This project required me to refresh my memory on how to tap a 4-40 hole.  I went back and watched the short video I made on the tribal knowledge that Pete had shared with me.  Out came the Tap and Die gear and the machine oil.  The process went very smoothly.

Here is what I did to get the heatsink in place:

1) After removing the original heatsink, I gently bent the leads on the IRF510 so that the transistors outer edge would be flush with the edge of the PC board.
2) I put a strip of thick tape (Gorilla Tape) along the lower side of the heat sink. This will keep the heat sink from shorting to the chassis.
3) I placed the heatsink where I wanted it, and carefully marked where the mounting screw (through the transistor's tab) should go.
4) Drill!  Tap!  (see video)  https://www.youtube.com/watch?v=LuqliWT1k5A
5) I applied some heat sink compound (or Desitin!) and then attached the transistor to the heatsink.
6) I put a few drops of glue between the heatsink and the board and the chassis, just to mechanically stabilize it a bit.
7) Bob's your uncle.

It seems to work great.  The MOSFET stays cool. even after long "old buzzard" transmissions.  And I notice no stability problems.  It was fun  to put to use some tribal knowledge and refresh a mechanical skill.  

Friday, November 11, 2016

My Extroverted BITX40 -- On (but not in) a Box


I was going to put the BITX40 Module in a box today, but I just couldn't bring myself to do it. That board looks too good to be hidden inside a box.  So I put it topside. That's the analog VFO to the right. You can see a fan off to the left -- that is perhaps temporarily in lieu of a large heat sink for the final. You can see the two Gel cells in the background.  I am indeed running 24 volts to the final, and am putting out about 20 watts.  I had three nice contacts today on 40:  WB2RON up on Long Island said I was "20 over".  Later I worked W1SJ in N. Vermont -- I was 5-9.  Then -- icing on the cake -- DK1NO in Stuttgart.  I was 5-8.  TRGHS.

I kind of like this arrangement -- it has the "three dimensional" feel of an old tube rig.  This obviously wouldn't be good for portable operations, but I am not planning on going portable.   There is a lot of room under the chassis.   I could put a digital VFO in there and put in a switch so that I can easily go from digital to analog.



Thursday, November 10, 2016

Two Gel Cells and a Heat Sink -- BITX40 Power Hack

I blame Pete for this.  And Farhan.  Pete has been leading us astray with all his talk of high power linear amplifiers ("Two 813s kid, that's all you need!").  And Farhan practically pushed us beyond QRP limits by placing a separate DC power connector for the IRF510 final amplifier on his new BITX 40 Module board.  Farhan writes: 

There are jump-points from where you can add more modules like the DDS, more bands, better audio amplifier, etc. Imagination is your limit. You can separately increase the power amplifier's supply voltage to 25 volts to be more than 20 watts of power : You will have to add a better heat sink. The mods are on the way! (from hfsigs.com)

A while back Chris KD4PBJ sent me some very nice heat sinks -- one of those would fit quite nicely on the PA side of the BITX40 board.  And I just happen to have two 12V Gel cell batteries. One will power the board and the two together will power the IRF510.  With 20 watts out to my dipole I feel confident that I will WIN the upcoming ARRL Phone Sweepstakes (in my category: Homebrew VFO, Northern Virginia).  

Sunday, November 6, 2016

SolderSmoke Podcast #191 RIGS! REAL RIGS!, BITX40 Module, EMRFD, MAILBAG


SolderSmoke Podcast #191 is available:

http://soldersmoke.com/soldersmoke191.mp3

TRAVELOGUE AND FAMILY DOINGS:   Pete son's wedding, Billy's Birthday, Gonzalo safely home in the Dominican Republic, MORE BEARS IN THE SHENANDOAH WOODS

BIG NEWS:  EMRFD LIVES ON!   Three cheers for Wes and for Tom Gallagher of the ARRL.

BENCH REPORTS:

PETE:   FPM Rig.  Some Halli history.  A TRUE RIG!  Working Japan. 
             WITH 600 WATT LINEAR AMPLIFIER!!!!!!!!!!!!!!!!!!!!!!
               New FEELTECH  Sig Gen.  

BILL: Farhan's BITX Module
           Built to Mod, built to get you started in homebrew
           Very impressive.  BITX in miniature.  But completely recognizable.
           REMARKABLY stable.
           Farhan personally checking each one.
           Ladies collective doing toroids.  DONATION money bought them some Diwali candies!
           VFO Drift:  Will NP0 SMD caps and lower current help enough?
           My Analog VFO -- BANDSWEEP

QRPppppppppppp  with REX's Hamfest Buddy.   Thanks Rex and Bob Crane.

HB2HB with KW4KD

MAILBAG
Jan's Netherland Mate Mighty Midget
Charlie's Kiwi DSB
Steve, Donald Fagan, and Jean Shepherd
Rob VK5RC repairs Tek Tube 'scopes
Colin M1BUU Si5351 superhet
Denis Klipa and NRL 3538
Jonathan M0JGH Wizard of Wimbledon Matchbox rig
JH8SST Simpleceiver
Peter Parker Vk3YE Reviews Book
Peter GW4ZUA Welsh LBS
Michael Rainey helping hobbyist in Germany with tuning forks.





Thursday, November 3, 2016

Reverse Polarity Protection

When I opened the package from India and saw Farhan's s beautiful board with all those little SMD parts, I immediately worried about frying those parts by accidentally reversing the polarity of the 12 volt DC input.   Believe me, this can happen.  It is especially likely during the early, enthusiastic testing and experimenting that takes place in the days after the arrival of a new rig.  So, my friends:  Save yourselves the agony of fried components!  Don't let your BITX 40 Module go up in smoke!  Install a simple reverse polarity protection circuit BEFORE you start working with your new board. 

Here is what I did:   I just took a diode (a fairly hefty diode) and I soldered it in between the pins of that neat little circular power jack that Farhan sent with the module.  Be sure to solder it in so that it does NOT conduct if you have connected the power correctly.  The arrow should be pointing to positive terminal.  Then put a fuse (3 amp or even a 2 amp) in the line from the connector to the power supply or battery.  If you don't have a holder you can try just soldering the fuse into the line.

With these two little parts, you can save yourself a lot of grief:  If (WHEN!) you connect red to black and black to red, that diode will conduct like crazy and will blow the fuse.  You'll just have to replace the fuse (and not the module).

Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column